The present invention relates to restraint device for restraining a vehicle to a fixed structure, and more specifically to a restraint device for restraining a vehicle, such as a truck, to a loading dock.
At loading docks, there is an eminent danger that a truck might leave the loading dock while a loading/unloading operation is in process. For instance, the truck driver may think that the loading/unloading process is completed and thus starts to drive away from the loading dock. Such situation creates a real danger for personnel using lift trucks to transport and load merchandises into the truck. Indeed, if an unexpected departure of the truck from the loading dock happens, this could cause the lift truck to fall off the loading dock.
Therefore, a popular way for preventing such accidents from happening is the use of a device that engages the ICC-bar on the rear of the truck to lock the truck next to the loading dock.
Already known in the prior art, there are restraint devices comprising a movable hooking device operated either manually or automatically with an automatic control. Examples of these prior art devices are disclosed in U.S. Pat. No. 5,120,181; 5,454,682; 5,336,033 and 6,062,796. In use, the truck is backed into position in front of the loading dock. Then the operator activates manually or electrically the hooking device in a restraining position in engagement with the truck ICC-bar and locks the hook in this position. When the loading is completed, the hook is manually or electrically released and returned to its stored position.
Other vehicle restraining devices have been proposed in which the actuation of the restraining devices is induced by the contact of the ICC-bar with the device. Examples of these types of devices are shown in U.S. Pat. Nos. 4,695,216 and 6,116,839.
The activation of the device may also be directly actuated by the dock leveller. Such a device is disclosed in U.S. Pat. No. 4,488,325. In this case, movement of the dock leveller""s lip actuates an electric circuit by means of a limit switch providing power to a motor in order to move the hook up and down.
While the restraining devices known in the art have resulted in the advancement within the present field, most of these prior art devices generally require motors, pneumatic or hydraulic activating systems. They are indeed very complex, thus expensive to manufacture and difficult to operate.
Therefore, there is still a need for a truck restraint device that is simple to operate, easy to manufacture and does not require motors, pneumatic or hydraulic activating systems to be activated.
It is therefore an object of the present invention to provide a restraint device for restraining a vehicle to a fixed structure that will overcome these drawbacks.
In accordance with the present invention, that object is achieved with a restraint device which comprises a frame securable to a fixed structure and a pivot member having a first end pivotally secured to the frame and a second end with a hooking member opposite the first end. The pivot member is pivotable on the first end between an upwards operative position and a downwards inoperative position. The device also comprises biasing means for biasing the pivot member in the upwards operative position and means for bringing back the pivot member from the upwards operative position to the downwards inoperative position. The means for bringing back the pivot member from the upwards operative position to the downwards inoperative position comprises an actuator member mounted in the vicinity of the pivot member for vertical sliding movement with respect to the frame, the actuator member having a top end portion opposite a bottom end portion respectively located above and below the first end of the pivot member. The means for bringing back the pivot member further comprises a linking member having a first end pivotally connected to the bottom end portion of the actuator member and a second end opposite the first end pivotally connected to the pivot member at a location between the first and second end thereof. The actuator member is movable along a vertical line between an upwards position obtained when the pivot member is biased in the upwards operative position and a downwards position which causes the pivot member to move in the downwards inoperative position.
The present invention is also directed to a combination of a restraint device as described above with a dock leveller mounted on a loading dock with a low vertical wall and a floor, the restraint device being secured to the low vertical wall under the dock leveller. The dock leveller comprises a platform with a rear edge hinged to the floor of the loading dock and a front edge, the platform being pivotable around the rear edge between a raised position where the front edge is disposed away from the floor and a lowered position where the platform lies on the floor. The dock leveller also comprises a lip having a first edge hinged to the front edge of the platform and a second edge for engaging the top end of the actuator member of the restraint device. The lip is hanging in a pendant position along the vertical wall when the platform is in the lowered position with the second edge engaging and pressing on the top end of the actuator member thus maintaining the pivot member in the downwards inoperative position. When the platform is pivoted in the raised position, the lip is caused to move upwards thereby releasing the pressure on the actuator member which causes the pivot member to move in the upwards operative position.
A restraint device according to the present invention proposes innovative features that makes it simple to operate, easy to manufacture and does not require motors, pneumatic or hydraulic activating systems to activate the device.